The present invention relates to an apparatus for and method of selecting a target language equivalent of a predicate word such as a verb or adjective in a source language word string for use in a machine translation system, the source language word string including the predicate word and a non-predicate word such as a noun associated with the predicate word.
A method using a co-occurrence relation between words is effective for selection of a target language equivalent in a machine translation system. This method is, however, associated with the problem that a large amount of co-occurrence relation knowledge need be expressed and stored in a memory. Such a problem is solved by expressing a co-occurrence relation as a word-concept relation and storing, in a thesaurus, general-specific concept relation of words, for example as in Japanese Patent Laid-Open Publication JP-A-63-132379 (laid open on Jun. 4, 1988).
However, it is generally difficult to construct the thesaurus itself because of a necessity to properly select a word of general concept having a plurality of words of specific concept in a co-occurrence relation to the former.